Join Date: Sep 2007
Location: Sydney, Australia
Re: loss of performance- alfa 156 2.5 v6
If the air inlet pipe is split it will definitely lead to performance issues. It is easy to blame such issues on the MAF because the symptoms are similar. This is not surprising because the MAF provides the ECU with air / fuel mix requirements, since the inlet pipe is mounted after the MAF it will allow unmetered air to be introduced. In other words the mixture becomes lean. When the inlet tube on my 156 cracked I repaired it with rubber glue. I drove the car for at least 150000 km after that and it was fine. Try to repair the inlet tube first, if that doesn't restore performance then move onto other (more expensive) items such as MAF.
The other possibility that came to mind was that the MAF could have been cleaned prior to sale - sometimes this works and others it does not. This is not a practice that I would recommend.